SUMMARY: Here's a history of fluoridation, or the process of introducing fluoride into tap water.

Posted: June 10, 2015

When you think of water, words like "pure," "clear" and "natural" might come to mind, but in reality, tap water is often treated before it winds up in your drinking glass. That's not to say the label "clean" doesn't still apply, only that the water in your faucet is pure, plus something extra. So what exactly goes into drinking water? For decades, fluoride has been present. What circumstances led health officials to include fluoride in tap and how does it benefit your family's oral health? Here's a history of fluoridation, or the process of introducing fluoride into tap water:

An accidental, but important, discovery Back in 1901, the U.S. didn't really think about what was in drinking water. It was clean, and that's what mattered. But a young dentist by the name of Frederick McKay began paying closer attention to drinking water after he made some observations. McKay moved from the East Coast to Colorado Springs, Colorado, in 1901 to open a dental practice. Upon arriving in the city and working with patients, he noticed that many locals had brown stains on their teeth. The issue was so rampant that McKay labeled it as "Colorado Brown Stain."

However, no records held any clues as to what the cause could be. Patients guessed that bad fat, calcium-rich water or eating too much pork could have caused the problem. So, McKay began to investigate. Other local doctors weren't interested, so it took the young dentist eight years to find a research partner, and in 1909, his perseverance paid off. G.V. Black, a prominent dental researcher at the time, agreed to help. This led to years of working with different researchers (Black died in 1915), until McKay had his big break in the 1930s.

After trekking to Idaho and seeing that people there had no brown-stained teeth, McKay, with help from the Aluminum Company of America and the U.S. Public Health Services, compared water from Colorado Springs to that in Idaho and other locations. Turns out, fluoride, which is the element fluorine with an extra electron, caused browning of tooth enamel.

The fluoride, however, also protected tooth enamel from decay. Researchers and dentists took McKay's research and ran with it, discovering that fluoride may help prevent cavities as well.

The national situation So how did we get from Colorado Brown Stain to fluorinated water? The research that took place after McKay discovered fluorine in water revealed that many natural water sources, such as streams and lakes, naturally contained fluorine. This is because the mineral exists in rocks, and runoff puts the it into water. However, municipalities that didn't exist near streams and rivers didn't have fluorine.

After careful investigation, researchers discovered that people who lived near bodies of water that contained one part per million of fluoride had fewer cavities without adverse effects. So, the U.S. government decided to add this small amount of fluoride to all drinking water. And so, fluoride in the tap water was born. This measure reduced the occurrence of cavities for people who did not live near mineral-rich water sources.